VALID 12Z/23-12Z/24

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MONDAY AFTERNOON AND NIGHT... FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS-- FROM EASTERN NEBRASKA AND WESTERN IOWA... SOUTH INTO OKLAHOMA AND NORTH TEXAS... SEE MAP FOR DETAILS...

VAPOR CHANNEL IMAGERY INDICATES THE DEVELOPING LONG-WV TROF ACROSS THE EAST PACIFIC.

MODEL SOLUTIONS OVER THE PAST 36 TO 48 HOURS HAVE BEEN SURPRISINGLY CONSISTENT... GIVEN THE LONGWAVE NATURE OF THE TROF AND FORECAST VIGOROUS DYNAMIC NATURE OF THE SYSTEM. 0Z/21 NAM/GFS/ECMWF/GGEM ALL EXHIBIT GOOD TIMING WITH LONG-WV TROF ENTERING THE WEST COAST... AND LEAD SHRT-WV EXITS INTO THE WESTERN PLAINS SUNDAY NIGHT/MONDAY MORNING. AMONG ALL THE MODELS THE BEST CONSENSUS IS THE SREF... AND WILL BE USED FOR TIMING.

INITIAL LEAD SHRT-WV IS FORECAST TO EJECT ENE ACROSS THE NORTHERN ROCKIES AND INTO MT ON SUNDAY... INITIAL BAROCLINIC ZONE WILL DEVELOP ACROSS THE PLAINS FROM SATURDAY NIGHT/THRU SUN... WITH INITIAL WAA FROM THE PLAINS OF WEST TX-- NORTHWARD INTO THE WESTERN HIGH PLAINS OF WESTERN SD.. WHERE UPPER 40 TO LOWER 50 DEWPOINTS WILL BE POSSIBLE. CONTINUED SFC THRU H85 THET-E ADVECTION CAN BE EXPECTED ON SUNDAY... GIVEN ENCROACHING HEIGHT FALLS ACROSS THE ROCKIES... STRONG 50-60KNT SLY LLJ WILL CONTINUE THROUGH THE DAY SUNDAY... PROVIDING CONTINUED WAA.

PRIMARY SHRT-WV IS PROGGED TO ENTER THE WESTERN PLAINS LATE SUN NIGHT/MON MORNING... H85 LLJ IN PLACE IS FOECAST TO STRENGTHEN TO 50 TO 70KNTS THROUGH THE DAY... AIDING IN ADVECTION OF UPPER 50 AS FAR NORTH AS CENTRAL KS... WITH 60+ DEWPOINTS GENERALLY AS FAR NORTH AS I-40.

PLUME OF STEEP MID LEVEL LAPSE RATES 6.5-7.5C/KM ATOP MODEST BOUNDARY LAYER MOISTURE.. COMBINED WITH UPSTREAM GEOPOTENTIAL HEIGHT FALLS 80-120 METERS... MODELS SUGGEST A H5 90-100KNT SPEED MAX WILL EJECT OFF THE HIGHER PLAINS OF NM/CO INTO WEST TX/SW KS BY LATE MORNING MONDAY. THE COMBINATION OF AFOREMENTIONED THERMODYNAMICS SUGGEST MODEST SBCAPE 1000-1500J/KG... HOWEVER VERY STRONG DEEP LAYER SHEAR AND STRONG DYNAMICS FOR ASCENT... SUGGEST CONVECTION WILL LIKELY DEVELOP ALONG DRYLINE FROM WESTERN KS INTO WESTERN OK BY MID TO LATE AFTERNOON. SHEAR IN PLACE SUGGEST THE THREAT FOR SUPERCELLS... WITH DAMAGING WINDS.. LARGE HAIL.. AND ISOLATED TORNADOES POSSIBLE.

THIS SCENARIO WILL NEED TO BE REASSESSED AS MORE DATE BECOMES AVAILABLE.. IF BOUNDARY LAYER MOISTURE IS DEEPER THAN CURRENTLY FORECAST-- A MUCH LARGER SCALE SEVERE EVENT WILL BE POSSIBLE. STAY TUNED FOR LATE OUTLOOKS.

- WARNER 03/21/09